How to disable Public IM Federation (Consumer Skype) in Office 365

3. A new window will open. From here, click on the Skype for BusinessIcon under Admin Centers as shown below.

4. A new window will open. From here, click on organization and external communications. First uncheck the Public IM connectivity, then select Off completely from the drop-down menu, and click Save at the bottom.

Note: CallTower can submit the Consumer Skype Federation 24 hours after this change has been made.